Q:
I have a question about falling stars, I want to know if they
really exist. The stars are the most distant objects. The
light takes approx. 8 sec to reach Earth so when you see a
star falling how can it travel the short distance and yet be
visible when it is almost 10,000 cross light years
away?

A:
Despite what their name suggests, "shooting stars" or
"falling stars" are not stars at all, but bits of space
debris called meteors. Meteors, which are usually between the
size of a grain of sand and a pebble, create a brief streak
of light when they enter the Earth’s atmosphere at high
speeds and burn up.

Meteors are produced in large quantities when the Earth's
orbit takes it through an area of space filled with rocks and
dust in the tail of a comet. For example, the Leonid meteor
shower – so-called because the meteors appear to come
from the direction of the constellation Leo – is due to
a trail of debris left by Comet Tempel-Tuttle on its 33-year
orbit of the Sun. When the Earth passes through this stream
of rocks, dust grains, and gas every November, observers on
Earth can be treated to a wonderful show. The passage can
also be a hazard to spacecraft. For a description of how
Chandra’s team dealt with the latest encounter, see http://chandra.harvard.edu/chronicle/0401/leonids.html.